codice:
#include <stdio.h>
#include <string.h>


typedef struct PIANO_CARTESIANO
{
  int x, y;
}point;


int main()
{
    point couple[3];
    int i;
    for(i=0; i<3; i++)
    {
        scanf("%d", couple[i].x);
        scanf("%d", couple[i].y);
    }    
    return 0;    
}
gcc -Wall -O ciao ciao.c
ciao.c: In function ‘main’:
ciao.c:17: warning: format ‘%d’ expects type ‘int *’, but argument 2 has type ‘int’
ciao.c:18: warning: format ‘%d’ expects type ‘int *’, but argument 2 has type ‘int’
ciao.c:17: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result
ciao.c:18: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result
ciao.c:17: warning: ‘couple’ is used uninitialized in this function